Re: [FlyRotary] boost controllers

Rusty,

All boost controllers I have come = across work by modifying the pressure the waste gate controller is seeing to = ‘trick’ it into either staying closed, or staying open. All waste = gates will open if not kept closed by something. The spring that is used = is fairly stout. It has to work against both the intake manifold pressure = and the exhaust manifold pressure which are both working to open the waste = gate. But don’t just install a random spring – either it will be too = weak to do any good, or it won’t open the waste gate when it needs to and = you’ll blow an engine. (in other words, there is no perfect sized spring unless = it is acted against by the boost pressure.)

The stock waste gate controller is = about as light as it gets and you shouldn’t run into any problems with = the ~5-7 psi it usually dishes out. But if you wanted to decrease the boost = you could lengthen the actuating arm a little or change out the = spring.

Install the stock waste gate = controller, Rusty. It does little good to have a turbo that doesn’t produce any boost = and you can easily control your manifold pressure with the throttle (every = turbo car runs just fine idle). Also, keeping that waste gate closed at = low power settings will help quiet the exhaust.

David Leonard

The Rotary = Roster:

http://memb= ers.aol.com/_ht_a/rotaryroster/index.html

Greetings,

Has anyone ever seen an aftermarket boost controller = that uses a motor of some sort to directly drive the = wastegate?

I've found a couple of controllers that will = work as absolute pressure devices (HKS EVC IV atm, and EVC PRO), but they use a = stepper motor as a variable air leak for the normal wastegate = actuator. Even this would be a step forward, but I'd need an actuator with a light spring. Of course I can't tell how low these controllers will = regulate, since they only brag about the high end. Anyway, something else to = think about.

Speaking of light springs in the actuator, how light = could you go and still have it work? In other words, if there was = nothing hooked up to the wastegate lever, would it have a tendency to open, or close? I'm guessing that it would try to open, so you need some = spring pressure to hold it closed, but how much, I haven't a clue. As = usual, more questions than answers...

I'm starting to imagine a big RC servo being = controlled by some sort of electronics connected to a MAP sensor. Hey Tracy, how = about throw that into my EM-2 :-)

Rusty

The end is near... uhh, make that in sight = :-)